This invention relates to a flying spot telecine apparatus, and particularly to modification of existing flying spot telecine apparatus to increase the flexibility and usefulness of the apparatus in converting cinematographic film to video signals.
A flying spot telecine apparatus is one in which consecutive frames of cinema film are optically scanned in a raster fashion by a light beam of small cross section (flying spot). Picture information modulated onto the light beam from the film is converted by one or more opto-electronic detectors into electrical signals or video signals, and the signals are thereafter processed in a predetermined known manner.
The United States television standard for raster scanning comprises a five hundred twenty-five (525) line/sixty (60) field operation. The cinematographic film is normally driven at 24 frames per second through a conventional telecine apparatus for conversion to a video signal, the same rate at which the film is photographed.
It has become important for photographers and film makers to vary the transport speed of the film to obtain special effects. For example, moving objects shot at a slower than conventional speed will photograph differently depending on the relative motive speeds of the subject being photographed--a stick in motion, for example, may be more blurred in the film frame than the hand moving it.
The speed at which the film is photographed may vary substantially from the speed conventional telecine apparatus are designed to operate, and it has been found that present flying spot telecine apparatus have not been able to adequately handle the different speeds. For example, the speed of motion will vary with the ratio of the speed at which the cinematographic film was shot with the speeds at which the film is converted to video signals. If audio is simultaneously recorded with the film, an additional problem in translation is presented. Therefore, it is a purpose of the present invention to modify an existing flying spot telecine apparatus as enumerated herein. With the modifications to the existing apparatus to be disclosed, the apparatus are now able to operate at very slow speeds as well as high speeds.